| Message ID | 20210415100409.3977971-3-philmd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hw/elf_ops: clear uninitialized segment space | expand |
On Thu, Apr 15, 2021 at 12:04:09PM +0200, Philippe Mathieu-Daudé wrote: >From: Laurent Vivier <laurent@vivier.eu> > >When the mem_size of the segment is bigger than the file_size, >and if this space doesn't overlap another segment, it needs >to be cleared. > >This bug is very similar to the one we had for linux-user, >22d113b52f41 ("linux-user: Fix loading of BSS segments"), >where .bss section is encoded as an extension of the the data >one by setting the segment p_memsz > p_filesz. > >Signed-off-by: Laurent Vivier <laurent@vivier.eu> >Message-Id: <20210414105838.205019-1-laurent@vivier.eu> >[PMD: Use recently added address_space_set()] >Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> >--- > include/hw/elf_ops.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > >diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h >index 6ee458e7bc3..29f4c43e231 100644 >--- a/include/hw/elf_ops.h >+++ b/include/hw/elf_ops.h >@@ -562,6 +562,19 @@ static int glue(load_elf, SZ)(const char *name, int fd, > if (res != MEMTX_OK) { > goto fail; > } >+ /* >+ * We need to zero'ify the space that is not copied >+ * from file >+ */ >+ if (file_size < mem_size) { >+ res = address_space_set(as ? as : &address_space_memory, >+ addr + file_size, 0, >+ mem_size - file_size, >+ MEMTXATTRS_UNSPECIFIED); >+ if (res != MEMTX_OK) { >+ goto fail; >+ } >+ } > } > } > >-- >2.26.3 >
Le 15/04/2021 à 12:04, Philippe Mathieu-Daudé a écrit : > From: Laurent Vivier <laurent@vivier.eu> > > When the mem_size of the segment is bigger than the file_size, > and if this space doesn't overlap another segment, it needs > to be cleared. > > This bug is very similar to the one we had for linux-user, > 22d113b52f41 ("linux-user: Fix loading of BSS segments"), > where .bss section is encoded as an extension of the the data > one by setting the segment p_memsz > p_filesz. > > Signed-off-by: Laurent Vivier <laurent@vivier.eu> > Message-Id: <20210414105838.205019-1-laurent@vivier.eu> > [PMD: Use recently added address_space_set()] I agree that is a better way to do. thanks, Laurent > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > include/hw/elf_ops.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h > index 6ee458e7bc3..29f4c43e231 100644 > --- a/include/hw/elf_ops.h > +++ b/include/hw/elf_ops.h > @@ -562,6 +562,19 @@ static int glue(load_elf, SZ)(const char *name, int fd, > if (res != MEMTX_OK) { > goto fail; > } > + /* > + * We need to zero'ify the space that is not copied > + * from file > + */ > + if (file_size < mem_size) { > + res = address_space_set(as ? as : &address_space_memory, > + addr + file_size, 0, > + mem_size - file_size, > + MEMTXATTRS_UNSPECIFIED); > + if (res != MEMTX_OK) { > + goto fail; > + } > + } > } > } > >
On 4/15/21 3:04 AM, Philippe Mathieu-Daudé wrote: > From: Laurent Vivier<laurent@vivier.eu> > > When the mem_size of the segment is bigger than the file_size, > and if this space doesn't overlap another segment, it needs > to be cleared. > > This bug is very similar to the one we had for linux-user, > 22d113b52f41 ("linux-user: Fix loading of BSS segments"), > where .bss section is encoded as an extension of the the data > one by setting the segment p_memsz > p_filesz. > > Signed-off-by: Laurent Vivier<laurent@vivier.eu> > Message-Id:<20210414105838.205019-1-laurent@vivier.eu> > [PMD: Use recently added address_space_set()] > Signed-off-by: Philippe Mathieu-Daudé<philmd@redhat.com> > --- > include/hw/elf_ops.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
Le 15/04/2021 à 12:04, Philippe Mathieu-Daudé a écrit : > From: Laurent Vivier <laurent@vivier.eu> > > When the mem_size of the segment is bigger than the file_size, > and if this space doesn't overlap another segment, it needs > to be cleared. > > This bug is very similar to the one we had for linux-user, > 22d113b52f41 ("linux-user: Fix loading of BSS segments"), > where .bss section is encoded as an extension of the the data > one by setting the segment p_memsz > p_filesz. > > Signed-off-by: Laurent Vivier <laurent@vivier.eu> > Message-Id: <20210414105838.205019-1-laurent@vivier.eu> > [PMD: Use recently added address_space_set()] > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > include/hw/elf_ops.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h > index 6ee458e7bc3..29f4c43e231 100644 > --- a/include/hw/elf_ops.h > +++ b/include/hw/elf_ops.h > @@ -562,6 +562,19 @@ static int glue(load_elf, SZ)(const char *name, int fd, > if (res != MEMTX_OK) { > goto fail; > } > + /* > + * We need to zero'ify the space that is not copied > + * from file > + */ > + if (file_size < mem_size) { > + res = address_space_set(as ? as : &address_space_memory, > + addr + file_size, 0, > + mem_size - file_size, > + MEMTXATTRS_UNSPECIFIED); > + if (res != MEMTX_OK) { > + goto fail; > + } > + } > } > } > > It seems we need also the same kind of operation with the other branch of the if (rom_add_elf_program()), but I'm not sure where to do it: diff --git a/hw/core/loader.c b/hw/core/loader.c index d3e5f3b423f6..8146fdcbb7a0 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -1146,9 +1146,13 @@ static void rom_reset(void *unused) if (rom->mr) { void *host = memory_region_get_ram_ptr(rom->mr); memcpy(host, rom->data, rom->datasize); + memset(host + rom->datasize, 0, rom->romsize - rom->datasize); } else { address_space_write_rom(rom->as, rom->addr, MEMTXATTRS_UNSPECIFIED, rom->data, rom->datasize); + address_space_set(rom->as, rom->addr + rom->datasize, 0, + rom->romsize - rom->datasize, + MEMTXATTRS_UNSPECIFIED); } if (rom->isrom) { /* rom needs to be written only once */ Thanks, Laurent
diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h index 6ee458e7bc3..29f4c43e231 100644 --- a/include/hw/elf_ops.h +++ b/include/hw/elf_ops.h @@ -562,6 +562,19 @@ static int glue(load_elf, SZ)(const char *name, int fd, if (res != MEMTX_OK) { goto fail; } + /* + * We need to zero'ify the space that is not copied + * from file + */ + if (file_size < mem_size) { + res = address_space_set(as ? as : &address_space_memory, + addr + file_size, 0, + mem_size - file_size, + MEMTXATTRS_UNSPECIFIED); + if (res != MEMTX_OK) { + goto fail; + } + } } }